This invention is directed to a rigid folding carton, container, or box, formed from a one-piece blank of corrugated board and which is suitable for both the shipping and display of its contents. More particularly, this invention relates to such a carton possessing corner gusset elements extending substantially the full height of the expanded carton, said gusset elements imparting significantly increased vertical crush strength to the carton compared with the crush strength of essentially the same carton but one lacking said gusset elements.
A common type of folding, expandable, or knockdown carton is formed from a single blank of foldable corrugated board material and possesses four wall panels, the fourth of which possesses a tab, or strip, to provide a surface of attachment for an adjacent portion of the first wall panel, a bottom flap hingedly connected to the bottom of each of the four wall panels and a top, cover, or lid flap hingedly connected to the top of each of the four wall panels such that upon expansion of the carton, the four bottom and four top flaps come together to form, respectively, the bottom and the top, cover, or lid, of the carton.
The vertical crush strength of the aforedescribed common folding corrugated board is relatively modest and care must be taken to avoid vertically stacking so many of the filled cartons as will exceed the vertical crush strength of the individual units.
A number of arrangement are available for increasing the vertical crush strength of a folding container beyond the limits of the ordinary corrugated board carton. One of them, referred to as internal packaging, involves the use of die-cut corrugated board elements for providing additional crush strength. The manufacture of internal packaging is relatively labor intensive and involves greater material costs, factors which have tended to limit its application.
Other expedients which can be used to achieve increased crush strength include modifying such parameters of corrugated board construction as the weight of the paperboard and simply multiplying the layers of corrugated board, e.g., to provide a double-wall, triple-wall, etc., structure.
Yet another arrangement for increasing vertical crush strength in a corrugated board carton lies in the provision of two, three or more separate pieces from which the carton blank is fabricated. The specialized nature of the carton and the fact that two or more separate components are involved in its construction accounts for the limited application of this approach to carton design and manufacture. Expensive machinery is required for the assembly of a multi-piece carton and relatively low manufacturing rates, e.g., 1,000 units per hour and even less in the larger carton sizes, is fairly typical. Unsightly glued flaps on external panels, readily visible coarse perforated scores and a lack of full panels which might otherwise be used to effectively display product identification are among the negative characteristics of this type of container which tend to militate against its use for point of purchase displays.
Each of these solutions to the problem of inadequate vertical crush strength exacts a considerable economic penalty. In addition, the bulk of the corrugated board required to achieve the desired increased vertical crush strength makes machining of the board more difficult and detracts from its overall appearance, an obstacle to its use in cartons intended for point of purchase display.